This invention concerns cyclizing the reaction product of alkylene oxides and salicylic acid esters and polymerizing the product. German Pat. No. 2,037,017 describes the reaction of alkylene oxides and salicylic acid esters in the presence of amine catalyst to yield compounds of the formula. ##STR2## But the German Patent does not disclose cyclizing these compounds. These cyclized compounds may then be polymerized into polyesters.